Sweden’s military has announced that if it finds a suspect foreign vessel in the Stockholm archipelago, it is prepared to force it to the surface “with weapons if necessary”. “Our aim now is to force whatever it is up to the surface… with armed force, if necessary,” he added. He added that submarines are “extremely difficult” to find, and that Sweden has never succeeded in the past when it came to tracking them down. “And no one else has either,” he added. If the sub is indeed Russian, it would be quite a hit for Sweden, which in more than a decade of hunting Russian U-boats in the 1980s and early nineties, never succeeded in capturing one, except in 1981 when the U137 ran aground several miles from one of Sweden’s largest naval bases, triggering an embarrassing diplomatic stand-off for Russia.